blackball vs shun

blackball is a noun but shun is not a noun.

Word	Noun	Adjective	Verb	Adverb
blackball	Yes	No	Yes	No
shun	No	No	Yes	No

As verbs, blackball and shun are synonyms defined as:

Other synonyms of blackball include ban, banish, cast out, ostracise, ostracize.

blackball (noun)	shun (noun)
the act of excluding someone by a negative vote or veto

blackball (verb)	shun (verb)
expel from a community or group	avoid and stay away from deliberately; stay clear of
vote against; refuse to endorse; refuse to assent	expel from a community or group